1. Field of the Invention
The invention relates to an actuator configured to adjust the optical axis of a lamp unit as an output shaft of the actuator is moved in the front-rear direction by the driving force generated by a drive motor.
2. Description of Related Art
In some vehicular headlamps, a lamp unit including a light source and a reflector that reflects the light emitted from the light source is disposed in a lamp case formed of a cover and a lamp housing.
In some vehicular headlamps, a lamp unit is pivotably (tiltably) supported by a supporting member such as a bracket. The lamp unit is pivoted by the driving force generated by an actuator to adjust the direction of radiation of the light emitted from a light source of the lamp unit (refer to, for example, Japanese Patent Application Publication No. 2013-105594 (JP 2013-105594 A).
In the vehicular headlamp described in JP 2013-105594 A, the lamp unit is pivoted within a vertical plane by the actuator, whereby so-called leveling adjustment (leveling operation) is carried out to correct the deviation of the optical axis that varies depending on the weight of loads that a vehicle carries. On the other hand, the lamp unit is pivoted within a horizontal plane by the actuator, whereby so-called swiveling adjustment (swiveling operation) is carried out to change the direction of the optical axis in in response to a change in the travelling direction of the vehicle.
The above-described vehicular headlamps configured to adjust the direction of radiation of the light emitted from the light source include the following two kinds of vehicular headlamps: i) vehicular headlamps that have the function of carrying out the swiveling operation but does not have the function of carrying out the leveling operation; and ii) vehicular headlamps that have the function of carrying out the leveling operation but does not have the function of carrying out the swiveling operation.
An actuator of a vehicular headlamp having the function of carrying out only the swiveling operation includes components for the swiveling operation, but does not include components for the leveling operation. On the other hand, an actuator of a vehicular headlamp having the function of carrying out only the leveling operation includes components for the leveling operation, but does not include components for the swiveling operation.
For example, an actuator of a vehicular headlamp having the function of carrying out only the leveling operation includes a drive motor, which serves as a drive source, and various members that are operated by the driving force generated by the drive motor to cause a Iamp unit to pivot in the vertical direction. Therefore, there have been demands for simplification of the configurations of these members.